Console lamp assembly for edge lighting of instrument panels



June 22, 1954 F. A. HARRINGTON 1, 80

CONSOLE LAMP ASSEMBLY FOR EDGE LIGHTING OF INSTRUMENT PANELS Filed Feb. 13, 1951 r 2 Sheets-Sheet 1 INVENTOR.

June 22, 1954 F. A. HARRINGTON CONSOLE LAMP ASSEMBLY FOR EDGE LIGHTING 0F INSTRUMENT PANELS 2 Sheets8heet 2 Filed Feb. 13, 1951 INVENTOR. .fiarru z gfon.

Frank/1 BY /7 orne Patented June 22, 1954 CONSOLE LAMP ASSEMBLY FOR EDGE LIGHTING OF INSTRUMENT PANELS Frank A. Harrington, Brea, Calii-Z, assignor, by

mesne assignments, to Marco Industries Company, Beverly Hills, Calif., a corporation of California Application February 13, 1951, Serial No. 210,752

7 Claims.

This invention relates to console lamp units for the edge lighting of instrument panels. Edge lighting is utilized for Various purposes, such as, for example, in military aircraft, wherein a primary factor is the avoidance of any illumination that would be visible to an enemy plane or antiaircraft ground crew. The customary method of edge lightin the dials of an instrument panel is to utilize an instrument panel of transparent or translucent synthetic resin plastic material (having light transmitting properties such as those of the plastic material commonly known under the trade name Lucite) to engrave in the surface of the panel, the letters and figures that are to be illuminated, and to fill the engraved recesses with a light pigment. The pigment picks up the light rays that are transmitted edgewise through the panel and the engraved characters are thus made suificiently luminous to be easily read by the pilot without projecting any light rays of an intensity such as to be visible at a distance.

It is customary to employ, as the source of illumination, a small electric lamp bulb received in an opening in the instrument panel and having its filament disposed in the plane of the panel. The light rays are projected laterally from the lamp, traverse the opening around the lamp, and enter the panel through the circular edge thereof which defines the opening. The forward end of the lamp is covered by a light shield which prevents any direct rays from the lamp being projected beyond the plane of the instrument panel. The lamp assembly now in common use has one drawback which the present invention proposes to overcome, namely, the light shield head portion thereof is of sufiicient dimensions and projects sufficiently beyond the base of the panel to resemble an instrument knob and occasionally a pilot will accidentally gras the same (when intending to grasp one of the instrument knobs) and pull it loose.

With the foregoing in mind, a primary object of the invention is to provide a console lamp assembly for instrument panel edge lighting, having a head portion that is as small, inconspicuous and hard to grasp as possible.

A further object is to provide such a lamp assembly which is easily installed and removed.

Another object is to provide such a lamp assembly having a minimum number of parts and of relatively inexpensive construction.

A further object is to provide a lamp assembly adapted to afford a full 360 dissemination of light rays into the panel.

Other objects will become apparent in the ensuin specification and appended drawings in which:

Fig. 1 is an axial sectional view through a console lamp assembly embodying the invention, shown on a magnified scale;

Fig. 2 is a plan view thereof;

Fig. 3 is a side view of the lamp holder or case;

Fig. 4 is an axia1 sectional view of a console lamp embodying a modified form of the invention; and

Fig. 5 is a fragmentary axial sectional View of a console lamp assembly embodying another modification of the invention.

Referring now to the drawings in detail, I have illustrated, in Figs. 1, 2 and 3, as an exam- Dle of one form in which the invention may be embodied, a console lamp unit for edge lighting of an instrument panel of transparent or translucent material which is indicated generally by the numeral l0. Panel i0 is mounted against a sheet metal bulk-head or frame member I0, which may function as a ground in the electrical circuit of which the lamp unit forms a part. The lamp unit extends through an aperture H in the panels it and Ill, and embodies a midget lamp A having a glass bulb portion l2 which is disposed approximately in the plane of panel H], so that the light rays from its filament I3 may be projected across the opening ii, in the plane of the panel and enter the panel through the edge l4 thereof which defines opening H. The lamp includes a base portion it havin at its end a radially extending flange H5 and a button H, the latter constituting one of the electrical contacts of the lamp. Flange I5 is utilized as the other contact. The lamp is of conventional design and does not in itself constitute a part of the invention.

My improved lamp unit includes, in addition to the lamp A, a two part casing therefor including, in general, a filter jacket B and a socket jacket 0, in which the inner end of filter jacket B is adapted to be mounted.

Filter jacket B includes an intermediate filter tube portion I8 of transparent or translucent material. I prefer to employ a ruby red high temperature plastic, so that the light rays, with the exception of the red rays, are filtered out, and only the red rays are transmitted into the panel l0, red being at the low intensity end of the visibility range. The use of plastic material makes it possible to perform accurate machining operations on the filter section, or to mold it accurately and inexpensively.

The jacket B has a closed forward end portion It which is masked so as to function as a light shield to cut off all direct light rays projected forwardly from the lamp A. The masking is preferably accomplished by coating portion [9 with a black coating 26 of plastic or any other suitable opaque coatin material, although it is possible to construct the portion l9 separately from a body of opaque plastic material and adhesively secure it to the forward end of filter tube l8. In either case, portion 19 is, in effect, an integral part of jacket B.

Cap 19 includes a relatively thin head portion 2|, preferably of disc shape, and a reduced diameter neck portion 22 joining the same to filter tube [8. A resilient masking collar or washer 23, encircling reduced neck portion 22, is interposed between head 2i and the forward face of panel H], to provide a clearance space, axially, between head 2| and panel In, and to close that space against the transmission of any light rays therethrough from opening I l. Collar 23 is constructed of a freely flexible material, such as soft rubber or an equivalent plastic material, so that the clearance space between head 2| and panel l may be freely adjustable to compensate for irregularities in the panel assembly I0, I 0', and also to provide for ample manufacturing tolerances in the sections 13 and C of the lamp unit. Neck portion 22 is of smaller external diameter than filter tube i8, whereby there is defined, between the latter and head 2|, an annular groove in which the inner portion of collar 23 is captive so as to retain the collar on the filter jacket B as a part thereof. The material of the collar is of a material that is sufficiently resilient to allow stretching of the col- -lar over filter tube I8.

Socket unit C includes a plain tubular rear section 2 1, an intermediate section 25 having external threads 26 and internal threads 21, and,

at its forward end, a radially extending flange ternal threads 33 for engagement with socket threads 21.

Threaded portion 21 of socket unit C is of larger diameter than the inner wall of forward portion 24 of socket unit C, and is separated therefrom by an offset shoulder 34. Shoulder 34 functions as an abutment against which flange l6 of lamp A is pressed when filter unit B is screwed home in socket threads 21. Thus a solid electrical connection is established from flange It to the ground side of the circuit for energizing lamp A, which ground side is indicated at 35 in Fig. 1, being carried through socket unit C to panel it. The other side of the circuit, indicated at 35, is established through a terminal member 31 in which is secured one end of a metal bushing 38. A yieldable contact pin 39 is axially slidable in bushing 38, its forward end having a head d9 adapted to press against contact button I! of lamp A. Such pressure is developed by a coil spring ii surrounding pin 39 and engaged under compression between head 46 and the forward end of bushing 38. Head 40 has a forward face which is dished to establish a centering bearing engagement against button IT. The dished face provides for automatic centering of button ll on head til, resisting any tendency of the two to skid laterally and pass each other (which would result in shorting the circuit).

Bushing 33 extends through terminal 31 and through a series of Washers including insulating washers 42, 43 and 44 mounted in the rear end portion of socket unit C. Rear end portion 24 has an inwardly projecting flang as which is embraced between washers 2 and 44, with intermediate washer 43 filling the end opening defined inside the flange 5. The ends of bushing 38 are flanged outwardly to retain terminal 3? and washers 42, 43, 44 in assembly.

It will now be apparent that filter tube l8 and end member :8 cooperatively define a tubular recess, closed at the forward end, in which lamp A is received. Base portion l5 of the lamp, of slightly larger diameter than bulb i2, is snugly received in this recess.

Head 2| is relatively thin, and collar 23 has a bevelled rim extending outwardly from the periphery of head 2!, so that a minimum peripheral area is presented, minimizing the likelihood of the pilot or operator grasping the head 2| in mistake for an operating knob of his instrument panel.

The lamp assembly may be assembled readily in the instrument panel by passing socket unit C through opening I! (which is sufiiciently large to receive flange 28) and attaching lock nut 30. With the socket member C thus mounted in the panel, filter unit B may be removed at will by simply unthreading its rear end from thread 21. In removing the filter jacket, lamp A, being snugly supported within filter tube I8, is withdrawn along with it. Thus is becomes easy to replace a burned out lamp. Also, the assembly of the filter jacket B and lamp A through opening II and into socket unit C is facilitated by the simultaneous insertion of the lamp and the filter jacket, with the latter enclosing and supporting the former.

In the modified form of the invention shown in Fig. 4, the inner wall of forward portion 24' of socket unit C is of substantially the same diameter as thread 21, and a metal sleeve 34 is pressed against flange l6 by a coil spring 5| engaged under compression between the rear end of sleeve 34 and flange 45 of socket unit C'. This provides for yielding bottoming of the assembly of lamp A and filter jacket B against the shoulder defined by the forward end of sleeve 34, so as to establish a good electrical contact without the necessity for screwing the filter jacket B tightly to an exactly pre-determined point. Other features of this modified assembly are the same as shown in Fig. l.

Fig. 5 illustrates a further modification in which, instead of sleeve 34, there is utilized a coil spring 5| of sufficient length to extend,

Fig. 5 is a preferred form of the invention.

I claim:

1. In a console lamp assembly for the edge lighting of a light transmitting instrument panel having an opening therein, by means of an electric lamp having a base provided with a radially projecting contact member and an axially projecting central contact, in combination: a socket unit having means for mounting the same in said panel and having an open end adapted to register with said panel opening; means within said socket unit providing an electrically conductive abutment for engagement by said contact member, said socket unit having an internal thread disposed intermediate said abutment means and said open end thereof; contact means mounted in the other end of said socket unit, having a contact end for engagement with said central contact, and having spring means for urging it yieldingly toward such engagement; and a filter jacket receiving said lamp and embodying an imperforate tube of light filtering material adapted to transmit the light rays from said lamp radially across said panel throughout a full 360 are opening and into the panel, said tube being receivable through said panel opening, having a threaded end portion adapted to be threaded into said internal thread of the socket unit and to press said radially projecting contact member into engagement with said abutment means, and having at its other end an integral, light shielded, closed end portion for arresting the rays of light directed forwardly from said lamp and permitting only the said radially directed rays to escape, said closed end portion including a thin disclike head having a flange portion projecting radially from said filter tube; said assembly further including a yieldable collar of opaque compressible material of washer form interposed between the under side of said flange and the forward face of said panel to prevent the forward emission of light rays from said panel opening around the periphery of said closed end portion.

2. In a console lamp assembly for the edge lighting of a light transmitting instrument panel, having an opening therein, by means of an electric lamp having a base provided with a plurality of contact members, in combination: a socket unit having means for mounting the same in said panel and having an open end adapted to register with said panel opening; socket unit providing electrical contacts for e11- gagement respectively with said contact members; a filter jacket receiving said lamp and in turn received in said socket and through said opening, said jacket and socket having interengaging means for detachably connecting the jacket to the socket; said jacket embodying an imperforate tube of light filtering material adapted to transmit the light rays from said lamp radially across said panel throughout a full 360 are opening and into the panel, said tube passing through said panel opening in the installed position of said assembly, said jacket having at its other end an integral, light shielded, closed end portion for arresting the rays of light directed forwardly from said lamp and permitting only the said radially directed rays to escape, said closed end portion including a thin disc-like head having a flange portion projecting radially from said filter tube; said assembly further including a yieldable collar of opaque compressible material of washer form interposed between the" under side of said flange and the forward face of said panel to prevent the forward emission of light rays from said panel opening around the means within said periphery of said closed end portion, said closed end portion including a neck portion joining said head to said filter tube, said neck portion having an external diameter smaller than that of said filter tube so as to define between said filter tube and said head an annular recess, said yieldable collar having its inner portion received in said recess whereby said collar is captive on said jacket, the light filtering translucency of said tube extending substantially to the rear face of said washer. 1

3. A lamp assembly as defined in claim 2, wherein said recess is shallow and said collar is stretchable so as to allow said filter tube to be passed therethrough in the assemblying of said lamp assembly.

4. A lamp assembly as defined in claim 3, wherein said collar is of dished diametrical cross section, having in its inner face a dished recess and having a peripheral face which is bevelled from a minimum diameter starting substantially at the periphery of said flange and extending outwardly substantially to the plane of said rear face, whereby to define a thin, peripheral, generally conical rim that is readily yieldable to conform to the surface of said panel to efiect a light seal.

5. A lamp assembly as defined in claim 2, wherein said disc-like head has a coating of opaque material uniformly covering the same and providing the light shielding characteristics thereof.

6. A lamp assembly as defined in claim 2 wherein said disc-like head is uniformly of opaque material throughout the body thereof and is bonded to the forward end of said jacket.

7. In a console lamp assembly for the edge lighting of a light transmitting instrument panel having an opening therein, by means of an electric lamp having a base provided with a radially projecting contact member and an axially projecting central contact, in combination: a socket unit having means for mounting the same in said panel and having an open end adapted to register with said panel opening; means within said socket unit providing an electrically conductive abutment for engagement by said contact member, said socket unit having an internal thread disposed intermediate said abutment means and said open end thereof; contact means mounted in the other end of said socket unit, having a contact end for engagement with said central contact, and having spring means for urging it yieldingly toward such engagement; and a filter jacket receiving said lamp and embodying an imperforate tube of light filtering material adapted to transmit the light rays from said lamp radially across said panel opening and into the panel throughout a full 360 are, said tube being receivable through said panel opening, having a threaded end portion adapted to be threaded into said internal thread of the socket unit and to press said radially projecting contact member into engagement with said abutment means, and having at its other end an integral, light shielded, closed end portion for arresting the rays of light directed forwardly from said lamp and permitting only the said radially directed rays to escape, said closed end portion including a thin disc-like head having a flange portion projecting radially from said filter tube; said assembly further including a yieldable collar of opaque compressible material of washer form interposed between the under side of said flange and the forward face of said panel to prevent the forward emission of light rays from said panel opening around the periphery of said closed end portion, the translucency area of said tube extending substantially to the rear face of said washer; said socket unit terminating at the plane where its said mounting means meets the plane of said panel; and said tube being of smaller diameter than said socket unit and therefore of smaller diameter than the panel opening, whereby to provide for an annular air space between said tube and the edge of the panel defining said opening, across which the light rays will traverse before entering thepanel.

References Cited in the file of this patent Number UNITED STATES PATENTS Name Date Batcheller Mar. 1, 1938 Foute Nov. 5, 1940 Blake Aug. 19, 1941 Douglas Apr. 7, 1942 Grimes Jan. 25, 1944 Rylsky Dec. 31, 1946 Paulus Apr. 27, 1948 Suwa June 14, 1949 Neugass May 6, 1952 

